1. Field of the Invention
The present invention relates to cameras, and in particular relates to the structure of a lens barrel of the camera and the arrangement of electric members in the lens barrel of the camera.
2. Description of the Related Art
Cameras have been widely used in practice in which a subject image formed based on a light beam incident on a photographing optical system composed of a plurality of lens groups is formed on subject-image obtaining means, such as an image pickup element of a charge coupled device (CCD) or a light-receiving plane of a photosensitive material such as a picture film, so as to obtain desired subject image information or subject images.
In such cameras, further miniaturization of the camera, especially in the thickness direction, has been required. To this end, compactification of the lens barrel including the photographing optical system has been indispensable.
With regard to the lens barrel used in such cameras, the miniaturization is proposed by applying a so-called bending optical system thereto, in which a reflection member such as a reflection mirror is arranged on a photographing light path including a plurality of lens groups so as to bend a photographing optical axis in a predetermined direction, for example.
The lens barrel described above generally houses therein a light-quantity adjusting device, such as a shutter and a diaphragm, for adjusting the light quantity corresponding to subject brightness and a lens drive mechanism for focusing and variable magnification.
A lens barrel incorporating the bending optical system is proposed in Japanese Unexamined Patent Application Publication No. 11-84209, wherein a subject beam is taken in by a prism and a photographing optical axis is bent by the prism so as to make the subject beam incident on an optical system composed of a plurality of lens groups. The optical axis incident on the prism designates a first optical axis and a bent optical axis passing thorough the plurality of lens groups denotes a second optical axis.
In the lens barrel mentioned above, the diaphragm unit is arranged between the plurality of lens groups, and a diaphragm blade of the diaphragm unit is displaced by a diaphragm drive source in a direction parallel to the first optical axis so as to adjust the light quantity. Furthermore, by zoom/focus motors, focusing drive and variable magnification drive in the second optical direction are carried out. The diaphragm drive source and the zoom/focus motors are arranged at corners of a rectangular parallelepiped with the first optical axis as its center. Electrical members are attached to fixed members and connection FPCs need not to move within the lens barrel, so that a structure for preventing an FPC (flexible printed circuit board) from entering an optical path is not necessary.
A lens barrel is disclosed in Japanese Unexamined Patent Application Publication No. 6-242491, in the lens barrel a shutter drive source is arranged on a frame member of the lens barrel, and on the frame member a lens frame thereby driven for focusing in the optical axial direction with respect to the frame member and a shutter device moving integrally with the lens frame are arranged. In this lens barrel, since the drive source is not arranged on the movable lens frame, a connection flexible printed circuit board (referred to as a FPC below) for the drive source does not need to be attached on the movable lens frame. Also, the connection FPC need not move within the lens barrel, eliminating a structure preventing the FPC from entering an optical path. Thus, in this conventional lens barrel, a structure around the lens frame is simplified, resulting in reduction in size.
In a lens barrel disclosed in Japanese Unexamined Patent Application Publication No. 5-134159, a shutter-drive FPC is connected to a shutter unit moving back-and-forth along the optical axis together with a lens frame. The shutter-drive FPC is structured in a specific shape so as to become deformed such that it does not enter a photographing optical path following shutter movement.
An electronic camera (electronic image pickup apparatus) disclosed in Japanese Unexamined Patent Application Publication No. 11-196303 includes a lens barrel housed therein and having a so-called bending optical system in which a subject beam along a first optical axis taken in by a prism is bent in a second optical axial direction orthogonal to the first optical axis so as to make the subject beam incident on an optical system composed of a plurality of lens groups. In this electronic camera, an electric circuit board having a notch extending over both lateral sides of the lens barrel is arranged. Furthermore, in the rear of the electric circuit board and the lens barrel, an LCD display unit is arranged, reducing the camera in size and thickness.
Moreover, an electronic camera disclosed in Japanese Unexamined Patent Application Publication No. 2000-10165 includes a lens barrel housed therein and having a so-called bending optical system, wherein a subject beam along a first optical axis taken in by a prism is bent in a second optical axial direction orthogonal to the first optical axis so as to make the subject beam incident on an optical system composed of a plurality of lens groups. In this electronic camera, an electric circuit board having a notch extending over both lateral sides of the lens barrel is arrange. In the rear of the electric circuit board and on the left of the lens barrel, a power supply battery is arranged while in the rear of the lens barrel and on the right of the electric circuit board, an LCD display unit is arranged, reducing the camera in size and thickness.